Aeration hood assembly



July 11, 1967 c. c. GRIFFITH AERATION HOOD ASSEMBLY Filed Sept. 29, 1965 In v e n10 r Charles Coleman Griffith his After United States Patent 3,330,119 AERATION HOOD ASSEMBLY Charles C. Griffith, 450 W. Broad St., Falls Church, Va. 22046 Filed Sept. 29, 1965, Ser. No. 491,285 7 Claims. (Cl. 61-1) This invention relates to circulators for causing the surface water of a pond to move in a single directional, i.e., clockwise or counterclockwise, endless path and has for its principal object the provision of a hood assembly equal or superior in efliciency to those now on the market but costing appreciably less.

In the drawings:

FIGURE 1 is a front elevation of a circulator as installed in a pond;

FIGURE 2 is a central vertical section, partly in elevation; and

FIGURE 3 is a view taken on line 3-3 of FIGURE 1.

Each circulator of a group reaching a hundred or more consists of a hood supported between stakes 11 driven a suitable distance into the ground 12 below the bottom 14 of the pond 15 and having spaced securing means, conveniently being U-bolt clamps 16 and 17 so located that the hood may be raised or lowered by workmen in a boat without the necessity for the workmen to enter the water. The hood carries a diffuser tube assembly 20 located at a chosen distance either slightly above or below the level of the bottom 21 of the hood, no claim being made as to the specific structure of the diffuser as this follows usual practice, its purpose being to cause an appropriate quancity of air to pass through the diffuser tube or tubes and thus create a flow of water through the hood and in such passage changing its direction from vertical to horizontal and discharging close to the water level in the pond.

The hood is preferably of eighth-inch thick steel plates, all except the rear wall being flat sheets. This rear Wall 19 is curved as at 24 tangent to its horizontal upper portion 25 and to its somewhat longer lower portion 26. This curved rear wall preferably extends forward beyond the vertical front wall a few inches to form a visor 31 so that the water flowing upward through the hood shall pass just about even with the water level 32 of the pond. The front wall 30 is about a foot short of touching the curved rear wall above thus providing a rectangular exit opening 33.

The two hood side walls 34 and 35 are welded to the curved rear wall at its edges but rather than following the curve, each has a horizontal face 37, a sloping face 38 and a vertical face 39 forming above an area 40 to secure the ends of a rolled steel shape 18 such as a channel, an angle iron, or preferably a more bar forming a strengthening member welded as at 43 to the two sides 34 and 35 and also at its lower edge to the curved rear wall 19 as at 44 (FIG. 3).

A vertical pipe 45 conveys air under pressure to the diffuser assembly 20 including the usual center fitting 47, end casting 48, tie rod 49, and hollow tubes which may each be 24 long, and with inside and outside diameters of 3" and 4%" respectively. For a hood 5 feet wide, 2 feet long and 5.5 feet high it is usual to have the diffuser tubes roughly a foot from the pond bottom level. The lower open end 12 of the hood has an entrance with an area of 10 square feet while the exit opening 33 need only be of half that area.

The nuts 52 of the two upper U-bolt clamps 16 are drawn up tightly while the similar nuts 54 of the lower clamps 17 are purposely locked loosely. This allows the hood to the be raised or lowered by workmen in a boat,

thus adjusting the height of the hood so that the visor 70 shall be positioned exactly at the water level, without ice touching the lower clamps usually say 4 feet or so below the water surface as these lower clamps merely prevent undue movement of the hood while readily allowing any needed up and down adjustment.

The stakes 11 are preferably much longer than normally needed and may extend well above the top of the hood and under some circumstances they should be guyed. The stakes may be pointed as at their bottoms 53 for ease in being driven into the ground. 'Piping of standard pipe of 1 /2" size is well suited to the task.

It is the general practice to install these circulators equally spaced longitudinally in an excavation for the pond before diverting the stream into it, hence, since the commercial diffuser tubes vary considerably in porosity it is important to be able to move a diffuser tube assembly up or down at a later date after the pond is filled, so as to vary the submergence of the diffuser, thus adjusting the amount of air to any single hood to accommodate variance in diffuser porosity or operational air distribution requirements.

This is advantageous as the diffusers of any one hood may be raised or lowered to increase or decrease the flow of air to secure a uniform flow at that particular point, or for example, when there are consecutive pools, one may wish to have all of the diffusers in the first pool a bit higher than those in the second pool, as the amount of air needed in the second pool is less because the initial load of settleable solids is less. Such up and down movement of the diffusers can be accomplished by U-bolts 56 with nuts 57 fastened to the member 18 and embracing the air pipe 45. By loosening the nuts 57 a Worker in a boat may readily assure that the entire flow is quite uniform.

While a single hood is shown, it will be understood that a considerable number of these will, in most instances, be utilized, preferably being placed at regularly spaced intervals in lines parallel to the shore line of the pond at perhaps a fourth of the distance across the pond from the shore, all aiming so as to provide a somewhat elliptical closed path. When all hoods are in place, some two or three hoods abreast in some cases, individual hoses from a suitable blower are attached to the air pipe 45 each with an individual valve and are then given final adjustment after which the upper clamps are tightly fastened.

What I claim is:

1. An aeration hood assembly for use in a pond to cause the surface water in the pond to move in a single directional (clockwise or counterclockwise) endless path, comprising (A) a hood body open at its bottom to be positioned in proximity to the bottom of the pond, said hood having parallel sides,

(B) a rear wall curved to deflect upwardly moving water within the hood to a horizontal direction and thus forming also a top wall,

(C) a vertical front wall extending from the level of the bottom of the sides and of the rear wall to a point short of the top wall to form an exit in a single direction for water flowing upward through the hood,

(D) a vertical air pipe passing through the curved rear wall near its top,

(E) a horizontal member permanently secured to the hood and adjustably holding the air pipe,

(F) a diffuser tube assembly arranged horizontally at the bottom of the air pipe,

(G) a pair of vertical anchoring stakes on each side of the hood to support the hood, and

(H) spaced securing means for supporting the hood on the stakes.

2. The assembly of claim 1 in which the spaced securing means fixedly secure the hood to the stakes near the pond water level and loosely secure the hood to the verti- 3 cal anchoring stakes near the level of the hood bottom, whereby adjustment of the height of the diffuser tube assembly may be made by workmen in a boat on the pond. 3. The assembly of claim 1 in which the 'hood is at least twice as wide as its length from front to back and the exit opening is at least /3 of hood length, and the parallel sides of the hood extend above and rearwardly of the curved rear wall to form fins.

4. The assembly of claim 1 in which the horizontal of the curved rear wall extends forward beyond the plane of the vertical front wall, forming a visor.

7. The assembly of claim 6 in which the visor is horizontal.

References Cited UNITED STATES PATENTS 2,827,268 3/1958 Stall 61-1 X 2,991,622 7/1961 Oster 61-1 3,109,288 5/1963 Gross 6l--*l 3,148,509 9/1964 Laurie 61-1 X 3,193,260 7/1965 Lamb 261 -64 EARL J. WIT MER, Primary Examiner. I 

1. AN AERATION HOOD ASSEMBLY FOR USE IN A POND TO CAUSE THE SURFACE WATER IN THE POND TO MOVE IN A SINGLE DIRECTIONAL (CLOCKWISE OR COUNTERCLOCKWISE) ENDLESS PATH, COMPRISING (A) A HOOD BODY OPEN AT ITS BOTTOM TO BE POSITIONED IN PROXIMITY TO THE BOTTOM OF THE POND, SAID HOOD HAVING PARALLEL SIDES, (B) A REAR WALL CURVED TO DEFLECT UPWARDLY MOVING WATER WITHIN THE HOOD TO A HORIZONTAL DIRECTION AND THUS FORMING ALSO A TOP WALL, (C) A VERTICAL FRONT WALL EXTENDING FROM THE LEVEL OF THE BOTTOM OF THE SIDES AND OF THE REAR WALL TO A POINT SHORT OF THE TOP WALL TO FORM AN EXIT IN A SINGLE DIRECTION FOR WATER FLOWING UPWARD THROUGH THE HOOD, (D) A VERTICAL AIR PIPE PASSING THROUGH THE CURVED REAR WALL NEAR ITS TOP, (E) A HORIZONTAL MEMBER PERMANENTLY SECURED TO THE HOOD AND ADJUSTABLY HOLDING THE AIR PIPE, (F) A DIFFUSER TUBE ASSEMBLY ARRANGED HORIZONTALLY AT THE BOTTOM OF THE AIR PIPE, (G) A PAIR OF VERTICAL ANCHORING STAKES ON EACH SIDE OF THE HOOD TO SUPPORT THE HOOD, AND (H) SPACED SECURING MEANS FOR SUPPORTING THE HOOD ON THE STAKES. 